Abstract:

Objective ·To investigate the efficacy and safety of a dose-reduced, all-oral lenalidomide/melphalan/prednisone acetate (RMP) regimen in elderly and frail patients with newly diagnosed multiple myeloma (NDMM). Methods ·Elderly and frail NDMM patients who visited the Department of Hematology of Ruijin Hospital, Shanghai Jiao Tong University School of Medicine, and the Third People's Hospital of Kunshan from April 2018 to March 2024 were retrospectively included. Clinical data and laboratory indicators were collected, and all patients were treated with the RMP regimen. SPSS 27.0 and R software were used for statistical analysis. Independent t-test was applied to normally distributed quantitative data, Mann-Whitney U test to non-normally distributed quantitative data, and χ² test and Fisher's exact probability method to qualitative data. Kaplan-Meier survival curves and Log-rank test were used for survival analysis. Results ·Among the 22 elderly and frail NDMM patients treated with RMP, the median age was 76.3 (68.4, 95.0) years, and the median follow-up time was 25.5 months. The overall response rate (ORR) was 68.2%, and the rate of ≥ very good partial response (VGPR) was 36.4%. The median progression-free survival (PFS) was 20.53 months. The median PFS in the ≤75-year-old group was 25.23 (95%CI 12.95‒37.52) months, while in the >75-year-old group it was 18.23 (95%CI 14.86‒21.61) months. There was no significant difference between the two groups. The median PFS in the ≥ partial response (PR) group was 20.67 (95%CI 13.57‒27.76) months, and in the < PR group it was 8.53 (95%CI 6.48‒10.59) months, with a statistically significant difference (P=0.011). The median number of treatment courses was 11 (2, 24). The incidence of treatment-related hematological adverse events of all grades was 63.6%, and ≥ grade 3 hematological adverse events occurred in 18.2% of patients. The most common treatment-related adverse event (TRAE) in hematology was neutropenia (63.6%), of which ≥ grade 3 neutropenia accounted for 13.6%. Common non-hematological TRAEs included fatigue (22.7%), respiratory tract infections (18.2%), rash (18.2%), gastrointestinal reactions (18.2%), and thrombosis (13.6%). Six patients (27.3%) required dose reduction or treatment suspension due to severe TRAEs. Conclusion ·The dose-reduced, all-oral RMP regimen is safe and effective in treating elderly and frail NDMM patients and is worthy of clinical application.

Key words: elderly frail, newly diagnosed multiple myeloma, lenalidomide, melphalan, prednisone acetate, dose-reduced